The present application relates to a retardation film using a liquid crystal material, a method of manufacturing the same, and a display using such a retardation film.
In recent years, the development of displays allowing three-dimensional display has been advanced. As a three-dimensional display system, for example, a system in which an image for the right eye of a user and an image for the left eye of the user are displayed on a screen of a display, and the user wearing a pair of polarized glasses views the images has been proposed as described in, for example, U.S. Pat. No. 5,686,975. This system is achieved by arranging a patterned retardation film in front of a display allowing two-dimensional display, for example, a cathode-ray tube display, a liquid crystal display or a plasma display. To control the polarization states of light entering the right eye and light entering the left eye, in such a retardation film, it is necessary to form a pattern of retardation or an optical axis at a pixel level of a display.
For example, in U.S. Pat. No. 5,686,975 and U.S. Pat. No. 5,327,285, techniques of forming the above-described retardation film by partially patterning a liquid crystal material or a retardation material with a photoresist or the like have been proposed. However, in such techniques, the number of process steps is large, thereby it is difficult to manufacture the retardation film at low cost. Therefore, in Japanese Patent No. 3881706, a technique of forming a retardation film by performing patterning with a photo-alignment film has been proposed. More specifically, the photo-alignment film is formed on a substrate, and then the photo-alignment film is patterned by a polarized ultraviolet ray. After that, the patterned photo-alignment film is coated with a liquid crystal material having polymerizability (hereinafter referred to as liquid crystalline monomer) so as to align liquid crystal molecules in a desired direction. After that, the liquid crystalline monomer is polymerized by irradiation with an ultraviolet ray, thereby the retardation film is formed. Moreover, in a liquid crystal display, a technique of performing patterning by performing a rubbing process on a polyimide alignment film is frequently used.